Leveling device to accommodate paper with at least two sections of different thicknesses

Abstract

A leveling device is useful for paper having at least two different thicknesses for a paper supply tray having a given depth, for a sheet feeder. This leveling device comprises a support upon which the paper having at least two different thicknesses rests, wherein the support height is self adjusting to compensate for the different thicknesses of the paper such that a top sheet of paper is in a position to feed properly into the sheet feeder.

What is claimed is:  
     
       1. A leveling device for paper having at least two different thicknesses for a paper supply tray having a given depth, for a sheet feeder, wherein the direction perpendicular to the direction in which the paper is fed into the sheet feeder is the crosstrack direction, wherein the paper has a width, a thinner portion and a thicker portion, and wherein the thickness varies in the crosstrack direction comprising: 
       a rectangular top plate having an edge one and an opposing edge two wherein said edge one and said edge two are perpendicular to the crosstrack direction, wherein said edge one and said edge two are separated by a distance which is less than the length of the thinner portion of the paper in the crosstrack direction, and the length of said top plate edge one and said top plate edge two is equal to or slightly less than the width of the paper, wherein said top plate is mounted to the paper supply tray such that it is not at the top of the depth of the paper supply tray, and not at the bottom of the depth of the paper supply tray, and such that said edge one lines up with the non-crosstrack direction edge of the thinner portion of the paper; and,  
       a rectangular pivot plate having an edge three and an opposing edge four, wherein said edge three and said edge four are perpendicular to the crosstrack direction, and wherein the length of said edge three and said edge four are equal to or slightly less than the width of the paper, and further wherein said edge three and said edge four are separated by a distance which is equal to or slightly less than the length of the paper in the crosstrack direction, wherein said pivot plate is pivotally mounted to the paper supply tray by a pivotal attachment means such that said pivot plate pivots about said edge three, and such that said edge three is directly under said top plate edge one, and wherein said pivotal attachment means is spring loaded such so as to be self adjusting to compensate for the different thicknesses of the paper such that when paper of two different thicknesses is loaded onto said paper tray such that the thicker portion is resting on said pivot plate, and the thinner portion is resting on said top plate, said pivot plate will rotate downward under the weight of the paper such that a top sheet of paper is in a position to feed properly into the sheet feeder.  
     
     
       2. The leveling device of  claim 1  wherein said pivot plate is bent into three parallel rectangular sections, section one, section two, and section three, wherein said edge three is on said section one, said edge four is on said section three, and said section two is between said section one and said section three, wherein the length of said section one in the crosstrack direction is approximately the same as the length of said top plate in the crosstrack direction, and the length of said section three in the crosstrack direction is substantially longer than the thicker portion of the paper, wherein said section one is parallel to said top plate, said section two angles away from the plane of said top plate, and said section three angles back up towards the plane of said top plate such that when there is no paper in said paper supply tray said pivot plate edge four is in the same plane as said top plate, and wherein no part of said pivot plate is above the plane of said top plate. 
     
     
       3. The leveling device of  claim 1  wherein said top plate has a bottom side, which is the surface facing said pivot plate, and wherein said pivot plate has an underside, which is the surface not facing said top plate, wherein said spring loaded pivotal attachment means comprises: 
       a pulley mounted to the underside of said pivot plate such that said pulley is also under said top plate, wherein said pivot plate has a slot located near said pulley;  
       a cable mounted to said top plate bottom side above said pivot plate slot, and wherein said cable is threaded through said slot, and threaded around said pulley; and,  
       a spring having opposing ends, end one and end two, wherein said end one is mounted to the paper tray, and said end two is attached to said cable such that when there is no paper in said tray the force of said spring on said cable around said pulley maintains said pivot plate in the desired position.  
     
     
       4. The leveling device of  claim 1  wherein said spring loaded pivotal attachment means further comprises: 
       a mount nut having opposing ends, end three and end four, wherein said end three has a threaded hole three, and said end four has a threaded hole four;  
       a connecting screw wherein the head of said connecting screw is attached to the spring end one, and the threaded portion of said connecting screw is threaded into said mount nut at the threaded hole four; and,  
       a mounting screw which mounts said mount nut to the paper supply tray by being threaded into said mount nut at said threaded hole three to achieve a desired pre-load on said spring such that when there is no paper in the paper tray the force of said spring on said cable around said pulley maintains said pivot plate in the desired position and when paper is resting on said support, a top sheet of paper is in a position to feed properly into the sheet feeder.  
     
     
       5. The leveling device of  claim 1  further comprising a rectangular bottom plate having an edge five and an opposing edge six, wherein said edge five and said edge six each span the width of said bottom plate, and wherein the length of said edge five and said edge six is equal to or slightly less than the width of the paper, and the distance between said edge five and said edge six is equal to or slightly less than the length of the paper in the crosstrack direction, wherein said bottom plate is parallel to said top plate, and wherein said bottom plate is the bottom of the paper supply tray. 
     
     
       6. The leveling device of  claim 5  further comprising: 
       a rectangular end plate which is perpendicular to said top plate and said bottom plate, wherein said end plate has a bottom edge and an opposing top edge, and wherein said end plate bottom edge is mounted to said bottom plate edge five, and such that said end plate bottom edge spans said bottom plate edge five, and wherein said top plate edge one is mounted to said end plate top edge such that said top plate edge one spans said end plate top edge, and wherein said pivot plate edge three is pivotally mounted to said end plate directly below said top plate edge one.  
     
     
       7. The leveling device of  claim 5  further comprising: 
       support members spanning between said top plate and said bottom plate, wherein said top plate is supported along the length of said top plate by said support members, such that the pivotal movement of said pivot plate is not interfered with by said support members.  
     
     
       8. The leveling device of  claim 7  wherein said support members are rectangular plates extending along the entire length of said top plate in the crosstrack direction. 
     
     
       9. The leveling device of  claim 5  wherein said bottom plate edge six is bent into two parallel rectangular sections, section four and section five wherein section four angles up into section five which forms a small ledge at edge six, wherein the combined lengths of said section four and said section five in the crosstrack direction do not exceed one inch.